When I tried to open my tenant via Cloud Computing Control Panel with Google Chrome, the other tenant which I didn't specify was opened.

Please use Firefox.

We acknowledged this issue and conducted the investigation and specified the cause.
The cause of this issue lies in the Referrer handling change in Google Chrome (after version85).

The upgraded Google Chrome doesn't send the tenant information to the authentication server when Customer selected their tenant and this causes that the customer can't open their selected tenant.

We are considering the countermeasures against this issue.
However, it will take time.
Due to the above, we'd like the customers to use Firefox when you access to your tenant via Cloud Computing Control Panel.

Thank you for your understanding and cooperation.